An experimental study to evaluate the effect of TiO₂ nanoparticles on the strength and stability of unidirectional glass fiber reinforced epoxy composites

The present paper discusses the improvement brought about in the strength and thermal stability of the unidirectional glass fiber reinforced epoxy composites through the incorporation of nano TiO₂. The hybrid nanocomposites are fabricated through wet lay-up technique and are cured under pressure and static loading at room temperature. The TiO₂ is added in 1, 2, 3, 4 and 5 wt% in order to arrive at the optimum wt% of nano TiO₂ for improvement in the desired properties such as bend strength, tensile strength and composite toughness. The uniform dispersion of nano TiO₂ into the epoxy matrix is achieved by sonication method. It is observed that the mechanical properties improved for TiO₂ addition up to 2 wt%. At 3, 4 and 5 wt% addition of nano TiO₂ the mechanical properties deteriorated due to severe agglomeration of the nano TiO₂ at higher loading. The agglomeration at higher loading is observed through the SEM and AFM images. The thermal stability of the hybrid nanocomposite is studied through thermogravimetric analysis and the results depicted an improved thermal stability at higher wt% addition of nano TiO₂ . This is because of the retardant effect exhibited by TiO₂ at higher wt loading to heat and oxygen. Hence, slowing down the thermal degradation of the composite. (paper)